A 30-year-old pregnant woman at 20 weeks gestation undergoes obstetric ultrasound. The placenta is located anteriorly and its lower edge extends to and covers the internal cervical os. What is this placental position called?
- A Placenta accreta
- B Placenta praevia ✓
- C Velamentous insertion
- D Succenturiate lobe
Correct answer: B. Placenta praevia
Explanation
Placenta praevia is defined as placental tissue overlying or immediately adjacent to the internal cervical os, diagnosed on ultrasound when the placental edge lies within 2 cm of or over the os. Major placenta praevia describes complete coverage of the os. It is a significant cause of painless antepartum hemorrhage in the third trimester and mandates caesarean section. Placenta accreta refers to abnormal invasion of the myometrium by placental villi. Velamentous insertion involves the umbilical cord inserting into the membranes rather than the placenta.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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